THEORY CONFIRMED BY PHENOMENA. 63 



are fully explained by a theory which accounts also for the 

 rain, I am sure he will not he very tenacious of his hori- 

 zontal whirlwind; especially when he does not pretend to 

 show that either the whirlwind is the cause of the rain, or 

 the rain the cause of the whirlwind. Let us, however, ex- 

 amine for a moment (for I should be proud to enlist Mr. 

 Redfield under the banners of a true theory) what would 

 be the phenomena, on the supposition that there is a hori- 

 zontal whirlwind, say of one hundred miles in diameter, 

 moving with a velocity of severity-five miles an hour, or 

 one hundred and ten feet per second. It is demonstrated in 

 mechanics, that if a body moves in a circle, with a diame- 

 ter of sixteen feet, and a velocity of sixteen feet per second, 

 its centrifugal force will be equal to its gravity. And as 

 centrifugal force is directly as the square of the velocity, 

 and inversely as the radius, the centrifugal force of the air 

 in this whirlwind is ascertained by the following proportion : 



16 .' * (g ravit y) I! 5*5280 '. 4 or yVthpart of the gravity. 

 And as a wedge of air fifty miles long is about eight 

 times as heavy as a column of atmosphere equal to its base, 

 its whole centrifugal force will be SXyV of fifteen pounds 

 to the square inch, which would cause the barometer to rise 

 about 1 T 4 <5- of an inch in the borders of the storm, both at its 

 commencement and termination ; and cause a motion of the 

 air outwards due to this pressure, which would be about 

 two hundred and eighty feet per second, according to the 

 principles of spouting fluids. Now these two phenomena 

 are entirely wanting in all north east storms ; for the air 

 does not blow outwards from the storm, nor does the ba- 

 rometer rise at the termination above the mean, though it 

 sometimes does at the commencement, for a reason which 

 shall hereafter be explained. Besides, if such a whirlwind 

 could be generated, it is manifest that it would soon be de- 

 stroyed by its outward motion, unless some mighty cause 



