ScHAW. — Circulation of the Atmosphere. 571 



faster, as in the voyage of 1897, in which a cyclone and its 

 following anticyclone overtook the ship. 



Our Australasian experience has shown us that the neutral 

 line between the anticyclones and the cyclones south of them 

 is variable within wide limits, and that occasionally the 

 centres of southern cyclones reach as far north as 47° or fur- 

 ther, and the northern boundaries of anticyclones occasion- 

 ally are displaced as far south as about 47° ; yet an anti- 

 cyclone lying altogether south of latitude 56° was to me at 

 least a new fact. 



It is no doubt possible that such southerly displacements 

 of the regular anticyclone belt normally lying in about latitude 

 35° may occasionally occur. We notice that in the voyage of 

 the " Aorangi," leaving Wellington on the 22nd December, 

 1893, an anticyclone extended for about fifteen hundred 

 miles south-eastward from Wellington, the south-east ex- 

 tremity being in latitude 56° ; but in the voyage of the 6th 

 July, 1893, we notice the ship passed the northern edge of an 

 anticyclone, in latitude 56J°, to the west and south of Cape 

 Horn. I feel constrained to regard this very far south anti- 

 cyclone, and probably many others observed in these voyages 

 in far southern latitudes, as belonging to a different category 

 from those to which we are accustomed in these latitudes, 

 and to indicate, as above mentioned, a second belt of anti- 

 cyclones lying south of the parallels of 50° to 55° south. The 

 observations of the limited number of explorers in antarctic 

 regions concur in noting very low barometer readings in the 

 summer in latitudes between 65° and 75° south, and hitherto 

 it has been supposed that a mean low barometer was to be 

 found in all the belt between that very far southern belt and 

 the vicinity of the ordinary anticyclone belt between 30° and 

 40° south. Now it would seem, however, that the atmo- 

 spheric circulation is soinetimes, if not always, more compli- 

 cated than had been supposed, and that between the " lows " 

 found in about latitude 45° and those found in about lati- 

 tude 70° there are generally to be found intermediate " highs," 

 in about latitude 60°. If " highs " and " lows " be viewed, as 

 I believe them truly to be, as positions in which there are 

 descending or ascending parts of atmospheric vertical circula- 

 tions, then it would seem that over these southern oceans 

 there is usually an intermediate vertical circulation between 

 the descending currents, aboiit latitude 35°, and the ascending 

 currents, about latitude 70°, which produces the normally high 

 and low barometric indications in those latitudes respectively, 

 and that this intermediate vertical circulation is indicated by 

 the high barometer with easterly winds frequently noted in 

 latitudes as far south as 56° or 57°. 



This seems to be the chief item of instruction to be gained 



