174 rnrsicAL geography of the sea, and its meteorology. 



360. At sea in the aouthei'n liemisphere ive have the rule, on land in 

 the northern the exceptions, as to the general circulation of the atmo- 

 sphere. — In the southern hemisphere, we may, by reason of its 

 great aqueous area, suppose the general law of atmospherical 

 moYoments to l)o better developed than it is in the northern 

 hemisphere. AV'e accordingly see by the table (§ 353) that the 

 movements north and south between 45° and 50° correspond 

 with the movements south and north between 25° and 30° ; that 

 as you go from the latter band towards the equator the winds with 

 southing in them increase, while the winds with northing in 

 them increase as you go from the former towards the pole. 



361. TJie magnetic poles, the poles of the ivind and of cold coinci- 

 dent. — This is the law in both hemispheres : thus indicating that 

 there must be in the polar regions, as in the equatorial, a calm 

 place, where these polar-bound winds cease to go forward, rise 

 up, and commence their return (§ 214) as an upper current. So 

 we have theoretically a calm disc, a polygon — not a belt — about 

 each pole. The magnetic poles and the poles of maximum cold 

 (§ 347) are coincident. Do not those calm discs, or " poles of 

 the wind," and the magnetic poles, cover the same spot, the two 

 standing in the relation of cause and effect ? This question was 

 first asked several years ago,* and I was then moved to pro- 

 pound it by the inductions of theoretical reasoning. Observers, 

 perhaps, may never reach those inhospitable regions with their 

 instruments to shed more light upon this subject ; but Parry and 

 Barrow have found reasons to believe in the existence of a per- 

 petual calm about the north pole, and later, Bellot has reported 

 the existence of a calm region within the frigid zone. Professor 

 J. H. CofSn, in an elaborate and valuable paper f on the " Winds 

 OF THE Northern Hemisphere," arrives by deduction at a like 

 conclusion. In that paper he has discussed the records at no 

 less than five hundred and seventy-nine meteorological stations, 

 embracing a totality of observations for two thousand eight hun- 

 dred and twenty-nine years. He places his "meteorological 

 pole " — pole of the winds — near latitude 84° north, longitude 106° 

 west. The pole of maximum cold, by another school of philo- 

 sophers, Sir David Brewster among them, has been placed in 

 latitude 80° north, longitude 100° west ; and the magnetic pole, 

 by still another school,J in latitude 73° 35' north, longitude 



* Maury's Sailing Directions. 



t Smithsonian Contributions to Knowledge, vol. vi., 1854. t Gauss. 



