-1859] WRITINGS OF JOSEPH HENRY. 283 



the belt of high barometer, (or that from which the air flows 

 out on each side north and south,) in summer extends beyond 

 the latitude of 40°, and thereb}' produces a wind from the 

 north in this season of the year, while in winter it is found 

 below Southern California, and thus gives rise along the 

 coast and parallel mountains of the interior to a wind in the 

 opposite direction, namely, from a southern point of the 

 compass. 



This is a sufficient explanation of the rain which falls at 

 that season, since the currents from the south are laden with 

 moisture which they deposit in their ascent along the slopes 

 of the mountains towards the north. 



On the drawing exhibiting the surface currents, (Fig. 6, 

 p. 276,) the point P representing the geometrical pole, is not 

 the centre of divergence of the aerial currents which settle 

 down in this region. The latter centre is that of the cold 

 pole, which probably on account of the unequal distribution 

 of land and the currents of the ocean, does not coincide with 

 the former. 



Climate of the United States. 



An application of the general principles we have given 

 will enable us readily to comprehend the peculiarities of the 

 climate of the United States, and to see how it must differ 

 from that of other portions of the globe. 



In order however to properly make this application, we 

 must briefly recall what has been said in previous papers* on 

 the circulation of the waters of the ocean, since they have a 

 powerful influence in the distribution of heat and the modi- 

 fication of different climates of the earth. For the more 

 definite comprehension of this, we have prepared a sketch of 

 the western hemisphere, shown in Fig. 9, on which the direc- 

 tion of the principal currents of the northern oceans are 

 denoted by arrows, and in explanation of these, we shall 

 briefly recapitulate the general theory of the cause and mo- 

 tion of these currents. 



If the equatorial regions of the earth were entirely covered 



[See a7ite, pp. 59-G2.] 



