THE WINDS OP THE SOUTHERN HEMISPHERE. 431 



years' experience at sea, I have never seen a tj^phoon or linrri- 

 cane so severe. Lost two men overboard — saved one. Stove 

 skylight, broke my barometer, etc., etc." Severe gales in this 

 part of the Atlantic — i. e., on the polar side of tlie calm belt 

 of Cancer — rarely occur during the months of June, July, 

 August, and September. This appears to be the time when the 

 fiends of the storm are most busily at work in the "West Indies. 

 During the remainder of the year, these extra-tropical gales, 

 for the most part, come from the north-west. But the winter 

 is the most famous season for these gales. That is the time 

 when the Gulf Stream has brought the heat of summer and 

 placed it (§ 172) in closest proximity to the extremest cold of 

 the north. And there should, therefore, it would seem, be a 

 conflict between these extremes ; consequently, great disturbances 

 in the air, and a violent rush from the cold to the warm. In 

 like manner, the gales that most prevail in the extra-tropics of 

 the southern hemisphere come from the pole and the west, i. e., 

 south-west. 



808. Storm and Bain cJiarts. — Storm and Eain Charts for the 

 Atlantic Ocean have already been published by the Observatory, 

 and others for the other oceans are in process of construction. 

 The object of such charts is to show the directions and relative 

 frequency of calms, fogs, rain, thunder, and lightning. These 

 charts are very instructive. They show that that half of the 

 atmospherical coating of the earth which covers the northern 

 hemisphere— if we may take as a type of the whole what occurs 

 on either side of the equator in the Atlantic Ocean — is in a much 

 less stable condition than that which covers the southern. 



CHAPTER. XX. 



§ 811-542. — THE WINDS OF THE SOUTHERN HEMISPHERE. 



811. Bepetition often necessary. — A work of this sort, w^hich is 

 progressive, must necessarily bear with it more or less of 

 repetition. It embodies the results of the most extensive sj'stem 

 of philosophical observations, physical investigation, and friendly 

 co-operation that has ever been set on foot. As facts are developed, 

 theories are invented or expanded to reconcile them. As soon 

 as this is done, or in a short time thereafter, some one or more of 



