16 THE OCEAN. 



is the rule, tlie European the exception. Wliat, then, 

 is the exceptional agency, which hlesses us with a 

 climate whose geniality would equal ten or twelve 

 degrees of latitude ? It is none other than the Gulf- 

 stream. This is in fact a vast hot water apparatus, 

 heated in the tropics, and then poured along the 

 shores of Europe, bringing with it its superincumbent 

 stratum of warm air. Tliis air, too, is diffused on our 

 shores rather than on those of America, by the preva- 

 lence of south and south-west winds, which blowing 

 in gusty gales, characterize the North Atlantic. The 

 influence of these winds is perceptible even as far 

 eastward as the borders of Eussia ; but it is much 

 •more powerful in the maritime parts, where the warm 

 water is constantly maintaining the elevated tempera- 

 ture of the air. 



Let us return, however, to consider the action of 

 the winds upon the sea, which, though affecting only 

 the surface, are the most powerful agents in producing 

 the irregular motions of this element. By them the 

 freighted bark, with her hardy crew, is wafted to the 

 wished-for haven ; and by them the crested billows 

 are roused up, which dash her upon the sharp-pointed 

 rocks, or swallow her up in fathomless depths, leaving 

 none to record her destiny. The origin of wind has 

 usually been attributed to the rarefaction of the air 

 by heat : a stratum of air near the earth being heated 

 by the sun's rays, or by radiation from the surface, 

 becomes hghter, and consequently rises to a higher 

 elevation. The empty space thus left is instantly 

 filled by the surrounding air rushing in, pressed by 

 the weight of the atmosphere above : this motion 



