THEORY OF HURRICANES, ETC. 335 



lantic between the United States and England, 

 that while one vessel encounters a thunder-storm, 

 others enjoy mild breezes within thirty or forty 

 miles of the same place. 



The same general agency, modified by the 

 relative position of land and water, oceanic cur- 

 rents, mountains and valleys, operates to a greater 

 or less extent over all the earth. Off Cape Hat- 

 terass, which is washed by the Gulf Stream, 

 there is a constant succession of gales r which are 

 obviously caused by the mingling of warm and 

 cold air, as seamen always observe a sensible 

 change of temperature on passing the Cape. The 

 same cause renders the Cape of Good Hope a 

 theatre of perpetual war of conflicting tempests, 

 occasioned by the difference of temperature be- 

 tween the great equatorial current, as it doubles 

 the Cape, and the colder water of the Southern 

 Ocean. 



There can be no doubt, that the amount of ca- 

 loric discharged in the form of lightning, during 

 extensive hurricanes, is in proportion to the 

 amount of condensation ; but its intensity or con- 

 centration is often less than during ordinary 

 thunder-storms ; because, during the former, the 

 electric fluid is attracted by a more extensive 

 mass of cloud, and is thus diffused. This also 

 explains why it is that the violence of lightning 

 and thunder usually abate after precipitation 

 becomes general. The electric matter, being 



