of the United States and the West Indies. 117 



eastvvardly direction, the wind on the central track of the storm will 

 commence from an eastern or north-eastern point of the compass, and 

 will gradually become south-easterly as the storm approaches its 

 height. 



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

 stated, will show conclusively that the portion of the atmosphere 

 which composes for the time being the great body of the storm, 

 whirls or blows in a horizontal circuit, around a vertical or some- 

 what inclined axis of rotation which is carried onward with the 

 storm ; that the course or direction of this circuit of rotation is 

 from right to left ; and that the storm operates in the same manner, 

 and exhibits the same general characteristics, as a tornado or whirl- 

 wind of smaller dimensions ; the chief difference being in the mag- 

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

 fully comprehended, affords a satisfactory solution of the otherwise 

 inexplicable phenomena of storms ; and will also be found to accord 

 entirely with the fact, which has been previously stated, that in the 

 phases or changes which pertain to a storm, the wind, on one mar- 

 gin of its track, veers in seaman's phrase 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 progress of any whirlwind which operates horizontally. 



12. The Barometer, whether in the higher or lower latitudes, al- 

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

 every part of its track, excepting perhaps, its extreme northern mar- 

 gin, and thus often affords us the earliest and surest indication of the 

 approaching tenipest. The mercury in the Barometer always rises 

 again during the passage of the last portion of the gale, and com- 

 monly attains the maximum of its erevation on the entire departure 

 of the storm. 



The great value of the Barometer to navigators is becoming well 

 understood, and its practical utility might be greatly increased by 

 hourly entries of the precise height of the mercurial column in a ta- 

 ble prepared for the purpose. Its movements unless carefully recor- 

 ded, often escape notice or recollection; which may easily happen 

 at those times when a distinct knowledge of its latest variations might 

 prove to be of the greatest importance. 



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

 storm is commensurate with the width of the track over which the storm passes. 



