xv 



dim-linn and tin- exceptional surface temperature. The descending air represents a supply to some 

 neighbouring low-pressure area, and the air so supplied will l>e subject to a certain though unknown 

 amount of dynamical warming. 



It is in accord with these ideas that the Antarctic anticyclone seems to be such an elusive object of 

 pursuit. Kverv Antarctic expedition gets almost within touch of it, but none actually grasps it. 

 Mi. |!KK\ \ITIII inferred it from the observations at Cape Adare; the inference is confirmed, although 

 not iniirh strengthened, by the observations at Koss Island, 400 miles further south, but, be it remarked, 

 along the coast line. The "Gauss," in the same way. got to the easterly winds in a much lower 

 latitude than the "Discovery." The "Discovery" found easterly winds when coasting along the ice 

 liarrier to King Edward VII. land. The " Scotia " found an increased barometric reading at her furthest 

 south (p. 451). It appears indeed to be possible that the limit of the low-pressure area defines the limit 

 that can be reached by a ship, and that wherever and whenever a ship is brought to a standstill by 

 permanent ice on its voyage south, the zone of lowest pressure is passed and the pressure has begun to 

 show an indication of anticylonic conditions. The easterly wind met with in these circumstances may 

 well be a general accompaniment of the pressure gradient associated with the transition from water to ice, 

 and therefore only local in so far as it is confined to a narrow belt just beyond the line of minimum 

 pressure. But whenever the limit has been passed, the temperature gradient ceases, and therewith the 

 pressure gradient ; and beyond the Winter Quarters of the ship, on the line of nearest approach to the 

 pole, wherever it may be, the pressure is generally uniform, with spasmodic gradients. 



It must be allowed that these are merely suggestions not fully worked out. There is material in the 

 observations now published for pursuing these ideas somewhat further. 



The whole question of local winds is one of great meteorological interest and importance, which has 

 long been noted for discussion in the Meteorological Office as soon as opportunity offers. 



I had hoped to have the opportunity of completing the discussion as regards Antarctic winds before the 

 publication of this volume, but, in the circumstances, it has not been possible, and to delay the publication 

 of the volume on that account would serve no useful purpose. 



W. N. SHAW. 



2-2in! Murrh, 1908. 



