INVESTIGATION 'OF STORMS. 177 



in others, and of course this circumstance would produce 

 just such irregularities as took place while the centre was 

 passing the different places. Sometimes the wind would 

 change by the north, and sometimes by the south, and 

 sometimes there would be a calm. As to the fall of the 

 barometer in storms, it was first suggested by Mr. Redfield, 

 that " the centrifugal influence which necessarily attends 

 the action of a whirlwind storm affords an obvious and 

 natural solution of this phenomenon." In this great storm 

 there was no centrifugal action, and therefore his solution 

 is not applicable to the present case. Indeed, the centrifu- 

 gal action cannot take place to cause a fall of the barome- 

 ter in case where cloud is formed. For if there is a centrifu- 

 gal action below, the air would descend in the middle, and 

 cloud could not be formed there. For, as the air descended, it 

 would come under greater pressure ; and if it descended to 

 the surface of the earth from a distance of six thousand 

 yards, it would be about 90 of Fahr. hotter by compression 

 than it was above, and then would be able to contain about 

 eight times as much vapor as it contained at its original 

 altitude, even if it was saturated there. Thus it appears 

 that in this storm, at least, the barometer did not fall from 

 any centrifugal action, for such action did not exist. Be- 

 sides, the grand, and as was supposed, fatal objection to 

 my doctrine, is refuted by the actual facts developed in this 

 storm. It was supposed by Sir John Herschel that, if the 

 wind blew towards a central space, the barometer would 

 certainly rise there above the mean. But the wind in this 

 storm did blow in with great violence to a central space, 

 and the barometer did not rise above the mean there, but 

 sunk lower as the wind blew harder. 



It seems to me much more philosophical to assign the fall 

 of the barometer as the cause of the wind, than to assign 

 the wind as the cause of the fall of the barometer. 



By a fall of the barometer, I mean a diminution in the 

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