314 Mr. Redfield's Reply to Dr. Hare. 



before him which are shown in my survey of the tornado, and 

 also with the numerous observations made in great storms, which 

 I have published, it is both vain and absurd to pretend that my 

 views of their rotation are founded only in imagination. I am 

 not conscious of having " built" or indicated any " theory," 

 views, suggestions or explanations of storms or whirlwinds which 

 have not been based on observations of my own and facts other- 

 wise ascertained, sufficient in my view to warrant them ; the 

 'unequal and opposing forces' even included: although, I have 

 not always urged these facts upon the attention of my readers ; 

 having, not unfrequently, reserved them for more appropriate oc- 

 casions. Hence, my alleged proofs have been chiefly confined 

 to the progressive course and rotative action developed in storms ; 

 which last, strangely enough, has been so pertinaciously denied 

 by Mr. Espy, and now by Dr. Hare. 



My opponent next attempts to show, " that any deficit of pres- 

 sure about the axis" of a whirlwind, "consequent to the resulting 

 centrifugal force, could only cause in the atmosphere a descend- 

 ing current, while it could not tend in the slightest degree to 

 carry solids or liquids aloft." p. 146. I was also surprised to find 

 this hypothetical downward current in the midst of a whirlwind 

 alleged as a necessary condition, on former occasions, by Mr. 

 Espy. If the allegation be true, it must be easy to show that 

 the ascending currents in chimneys should become inverted: for, 

 so far as simple gravitation is concerned, it can make little diifer- 

 ence whether the rarefaction be mechanical or calorific. 



But the ascending effects in the interior of a whirlwind have 

 been too often witnessed by myself and others to require discus- 

 sion. Indeed, it would almost seem that the objectors had been 

 precluded from all opportunities for correct observation. There 

 are numerous cases, however, in which the upward movement of 

 the objects elevated cannot be seen in the central and lower parts 

 of the whirlwind ; owing, as I have had good occasion to know, 

 to the great angular velocity of the central gyrations. 



Dr. Hare appears to suppose, that gyration in a revolving fluid 

 mass will not quicken as it approaches the center, unless as result- 

 ing from a centripetal force "caused by suction at the axis." 



A constant centripetal force I have already recognized on this 

 as well as former occasions. But this by no means requires or 

 produces a direct centripetal course in the moving air which 



