Hurricanes and Storms of the West Indies. Sll 



11. A full and just consideration of the facts which have 

 been stated, will shew conclusively that the portion of the at- 

 mosphere which composes for the time being the great body of 

 the storm, whirls or blows as above stated, in a horizontal cir- 

 cuit, around a vertical or somewhat inclined axis of rotation 

 which is carried onward with the storm ; that the course or di- 

 rection of this circuit of rotation is from right to lejl ; and that 

 the storm operates nearly in the same manner as a tornado or 

 whirlwind of smaller dimensions ; the chief difference being in 

 the more disk-like form of the whirling body and the magni- 

 tude of the scale of operation.* This view of the subject, when 

 fully comprehended, affords a satisfactory solution of the other- 

 wise inexplicable phenomena of storms, and will also be found 

 to accord entirely with the fact which appears in the above 

 statement, that in the phases or changes which pertain to a 

 storm, the wind, on one margin of its track, veers with the sun, 

 or from left to right, while under the opposite margin of the 

 same storm it veers against the sun, or from right to left ; for 

 this peculiarity necessarily attends the progressive action of any 

 whirlwind which operates horizontally. 



12. Owing to the centrifugal action of these rotative storms, 

 the barometer, whether in the higher or lower latitudes, always 

 sinks while under the first portion or moiety of the storm on 

 every part of its track, excepting, perhaps, its extreme outward 

 margin, and commonly affords us the earliest and surest indi- 

 cation of the approaching tempest. The mercury in the ba- 

 rometer always rises again during the passage of the last por- 

 tion of the gale, and commonly attains the maximum of its ele- 

 vations on the entire departure of the storm. 



The great value of the bai-ometer to navigators is becoming 

 well understood, and its practical utility might be greatly in- 



* It is to be understood that the diameter of the whirlwind which consti- 

 tutes the storm is commensurate with the width of the track over which the 

 storm passes. The main body of the storm is supposed to move in the form 

 of an extensive disk, whirling around its own centre as it advances in its re- 

 gular track — with this difference, that the rotative movement is far more ra- 

 pid in the interior portions of the whirling body, than towards its exterior 

 limits. 



