Tropical Cyclone. 



585 



course off the Atlantic border they also must shut off the 

 moisture from the northern states and tend to maintain 

 warm, dry weather there. 



Whether in this case the two systems of low areas were 

 the cause of the belt of high pressure whicli prevailed, or 

 whether the high pressure belt simply marks the place 

 where, for some reason, the upper air from the general 

 wind system was falling to the earth, the outcome, so far 

 as the weather is concerned, must be essentially the same. 



744. Tropical Cyclones. During the latter part of Aug- 

 ust, September and the fore part of October it frequently 

 happens that storms of unusual magnitude, intensity and 

 destructiveness originate in the north tropical zone of trade 

 winds, somewhere in or to the east of the Carribean Is- 

 lands and, after traveling westward with ihe prevailing 



FIG. 272. Path of West Indian Hurricane of An-. 7-14, 1899. 



winds of that zone, they finally make their way northward 

 across the tropical calm belt and break into the zone of 

 southwest Avinds, making their way northward and east 

 ward, as represented by the two storm tracks in Fiir.s. L'71 

 and 272, the former being the storm whicli PI-IM lured the 

 terrible destruction of life and property at Galveston on 



