Redfield's Theory of Storms. 101 



84. Mr. Redfiekl alleges, that the storm of August 17th, 

 1830, whirling to the left, travelled from south-west to north- 

 east at the rate nearly of twenty-seven miles per hour ; that 

 its greatest diameter was from five hundred to six hundred 

 miles ; that of its severe part was from one hundred and fifty 

 to two hundred and fifty miles. Thus it may be assumed, 

 that in order for an observer to be exposed successively within 

 the severe portion on the south-eastern and north-western 

 limbs, the storm would have had to move at least one hun- 

 dred miles, requiring nearly four hours. Hence if the storm 

 in question were a whirlwind, instead of the change having 

 been sudden, several hours would have been required for its 

 gradual accomplishment. 



85. To prove therefore that a sudden change ensued from 

 one violent wind to another of the same character blowing in 

 an opposite direction, is to demonstrate that the storm in which 

 it took place was not an extensive whirlwind. Yet this cha- 

 racteristic is universally admitted to belong to hurricanes, and 

 especially to those upon our territory in which a south-easter 

 is followed by a north-wester. Hence the seaman's saying 

 which Mr. Redfield sanctions in quoting, " a north-wester 

 does not remain long in debt to a south-easter." 



86. But if the storm above alluded to moved from south- 

 west to north-east as Mr. Redfield's doctrine requires, and the 

 velocity of the wind on the south-eastern and north-western 

 limbs of the whirl were as great as described, that on the 

 south-western side must have been more than a fourth more 

 violent, having the general motion of the storm superadded 

 to its appropriate gyrating velocity. Yet there is no evidence 

 that any such superiority existed. On the contrary, the vio- 

 lence of the south-easter and north-wester seems to have been 

 pre-eminently the object of attention. 



87. Agreeably to Mr. Redfield, hurricanes have a diameter 

 varying from one mile to five hundred miles, the diameter of 

 the severe part of the storm of August 1830, being from one 

 hundred and fifty to two hundred and fifty miles. Of course 

 a portion of the eastern as well as the western limb of such 

 a storm might be comprised between the Alleghany moun- 

 tains and the Atlantic shore; and in no case would the inner 

 portion of the south-eastern and more violent limb be beyond 

 the cognizance of our merchants and insurers. It would be 

 a matter of course that in every violent north-east gale, arising 

 as represented from the progression of the north-western limb 

 along our coast, fears would be entertained lest vessels, inward- 

 bound, should be met by a much more violent south-wester. 

 But experience shows, that every north-easter brings in a 



