Redfield's Theory of Storms. 99 



77. Considering the inconsistencies of Mr. Redfield's " re- 

 liable facts and observations," I hope I may be allowed to 

 show what ought to ensue according to his own premises. 

 Evidently in a whirlwind, constituted as are those to which 

 we have reference, the centrifugal force will cause an accumu- 

 lation of air towards the exterior until the otherwise uncoun- 

 teracted pressure of the accumulation, tending to restore the 

 level, is in equilibrio with the centrifugal force. Moreover, 

 the reaction of the fluid lying in the same plane beyond the 

 whirl, will cause the fluid to be higher, or if elastic, denser at 

 an intermediate point than the general level. In the case of 

 an elastic fluid like the air, condensation will be substituted 

 for accumulation, and will amount to the same thing in effect. 

 It would follow, that as the whirl should advance, the baro- 

 meter would rise until the front limb of the zone of greatest 

 condensation should arrive ; subsequently it would fall till the 

 central space should arrive, and then another rise and subse- 

 quent fall would ensue during the approach and departure of 

 the rear limb of the zone of greatest condensation. 



78. One fact is mentioned among the contradictory evidence 

 above quoted, which seems to be supported by universal ex- 

 perience. The barometrical column does fall at the com- 

 mencement of a storm, and of course this fact does not accord 

 with the idea that storms are whirlwinds produced by me- 

 chanical forces remote from the axis and attended necessarily 

 by a centrifugal action which would accumulate the air to- 

 wards the exterior. 



79. Respecting another characteristic, the " reliable facts 

 and observations of our theorist" are no less irreconcilable than 

 in the case last considered. I allude to the changes in the di- 

 rection of the wind which ensue from the commencement to 

 the end of a hurricane, and especially on the outer limbs on 

 each side of the line of progression. 



80. Thus, speaking of the progress of a storm from south- 

 west to north-east along the coast of the United States, he al- 

 leges that " along the central portions of the track the first 

 force of the wind is from a point near south-east, but after 

 blowing for a certain period it changes suddenly, and usually, 

 after a short intermission, to a point nearly or directly op- 

 posite to that from which it has previously been blowing ; from 

 which opposite quarter it blows with equal violence till the 

 storm has passed over or abated." Again, " It is demon- 

 strably evident, that at any point over which the centre of a 

 whirlwind may pass, the wind must suddenly change to a di- 

 rection almost exactly opposite to that which has been felt 

 during the preceding part of its progress." (Silliman's Journal, 



H2 



