86 



The lines of demarcation between them seem to be some- 

 what confused. But the following points seem pretty 

 clearly established. 



Tornadoes over the sea are accompanied often with one 

 or more complete water-spouts and over the land with 

 partial water-spouts or with columns of dust. There is 

 a close similarity of these phenomena. Tornadoes fre- 

 quently bursl forth upon the land suddenly, perhaps first 

 on the side of a mountain and moving forward along a 

 straight or curved track, with dark clouds moving to- 

 wards the sea, while a breeze may be blowing in an 

 opposite direction. They show their terrific force by over- 

 turning, uprooting, breaking or twisting off trees; by 

 demolishing buildings or lifting these and other heavy 

 bodies into the air to scatter their parts around at great 

 distances, or sometimes to set them down again nearly 

 unharmed; by lifting other objects, such as the beasts, 

 persons, and sometimes even large cannon, and trans- 

 porting them to considerable distances, destroying crops 

 and farm improvements of all kinds in their course. As 

 a rule the energy of the wind and the havoc it produces 

 are greatest near the circumference of the whirl, and 

 places over which at any moment its centre is situated 

 may experience for the time an almost total lull of 

 wind, to be renewed however in all its violence as the 

 posterior margin of the whirl reaches them. This whirling 

 motion is universal, and shows that the 1 phenomena are in 

 all cases associated with, or dependent on some form of 

 whirling wind. Abundant facts prove that very heavy 

 objects can thus be elevated and suspended for a consid- 

 erable time before they are allowed to fall, though we are 

 as yet unable to understand exactly in what manner so 

 great a lifting power is exerted on those objects. 



Hurricanes prevail more particularly, and with the 



