MAGNETISM AND CIRCULATION OF THE ATMOSPHERE. 145 



have a consistency sufficient, with the lights of reason, to guide 

 us as we seek to trace the wind in his circuits? The winds ap- 

 proach these polar calms (§ 155) bj a circular or spiral motion, 

 traveling in the northern hemisphere against, and in the southern 

 with the hands of a watch. The circular gales of the northern 

 hemisphere are said also to revolve in like manner against the 

 hands of a watch, while those in the southern hemisphere travel 

 the other way. Now, should not this discovery of these three 

 poles, this coincidence of revolving winds, with the other circum- 

 stances that have been brought to light, encourage us to look to 

 the magnetism of the air for the key to these mysterious but 

 striking coincidences ? 



385. Indeed, so wide is the field for speculation presented by 

 these discoveries, that we may in some respects regard this great 

 globe itself, with its " cups" and spiral wires of air, earth, and 

 water, as an immense "pile" and helix, which, being excited by 

 the natural batteries in the sea and atmosphere of the tropics, ex- 

 cites in turn its oxygen, and imparts to atmospherical matter the 



, properties of magnetism. 



386. With the lights which these discoveries cast, we see (Plate 

 I.) why air, which has completed its circuit to the whirl* about the 

 Antarctic regions, should then, according to the laws of magnet- 

 ism, be repelled from the south, and attracted by the opposite pole 

 toward the north. 



387. And when the southeast and the northeast trade-winds 

 meet in the equatorial calms of the Pacific, would not these mag- 

 netic forces be sufficient to determine the course of each current, 

 bringing the former, with its vapors of the southern hemisphere, 

 over into this, by the courses already suggested ? 



388. This force and the heat of the sun would propel it to the 

 north. The diurnal rotation of the earth propels it to the east ; 

 consequently, its course, first through the upper regions of the 

 atmosphere, and then on the surface of the earth, after being 

 conducted by this newly-discovered agent across the calms of 

 Cancer, would ho, from the southward and westward to the north- 

 ward and eastward. 



* "It whirleth about continually." — Bible. 



K 



