146 Objections to Mr. Redfield'S Theory of Storms. 



produced, not by a deficit of pressure about the axis, but by un- 

 equal and opposing forces acting externaily, in any competent 

 way whatever, is it not evident that any deficit of pressure about 

 the axis, consequent to the resulting centrifugal force, could only 

 cause in the atmosphere a descending current, while it could not 

 tend in the slightest degree to carry solids or liquids aloft? It must 

 be obvious, that the stratum of air on the earth's surface, partak- 

 ing of the circular motion, must also partake of the centrifugal 

 momentum, and of course would have the inverse of any dispo- 

 sition to rush towards the axis so as to be productive of a vertical 

 blast. Meanwhile the air being rendered rarer by the centrifugal 

 momentum imparted as above alleged, ponderable bodies envel- 

 oped by it would have their gravity less counteracted than usual, 

 and consequently far from acquiring any tendency to rise, would 

 be unusually difficult to elevate. 



28. I cannot help thinking that as respects the application of his 

 "rotary theory" to account for the upward movement which ap- 

 pears to be essential to tornadoes, these arguments will amount 

 to a " reductio ad ahsurdtmiJ^ 



29. Mr. Redfield infers that the whirlwinds of which he assumes 

 the existence, have a property which he alleges to be observable 

 in " all narrow and violent vortices," viz. " a spiral involute motion 

 quickened in its gyrations, as it approaches towards the centre of 

 the axis or whirl."* But is it not evident, that if any fluid mass 

 be made to revolve by unequal and opposing forces, or by any other 

 than those resulting from the centripetal force, caused, as already 

 described, by suction at the axis, the gyration will not quicken, in 

 proportion as the gyrating matter may be nearer the centre ; but on 

 the contrary, will be slower as the distance from the axis may be 

 less? It appears to me that the only case in which gyration is 

 found to quicken in proportion as the matter involved approaches 

 the vortex, is that which results from a confluence caused by an 

 ascending or descending current at the axis of the whirl. 



30. So far therefore as Mr. Redfield's observations confirm the 

 idea that the whirling motion in tornadoes quickens towards the 

 centre, it tends to confirm the opinions which he combats, and to 

 refute those which he upholds. 



31. Although the efforts which I have made to show that the 

 phenomena of tornadoes and hurricanes arise from electrical reac- 



* See this Journal, Vol. xxxi, p. 130. 



