429 



freshening to gale force of the wind, while veering from cast south-east, or south-south-east to south wc-t, 

 or south-south-west, pointing to the passage, seaward, of a low-pressure system across the Koss Sea. 

 During these gales atmospheric pressure fluctuated slightly, but was for the most part .steady, and 

 temperature rose as the wind veered to southward and south-westward. When the barometer showed a 

 decided rise the wind backed to the eastward of south and abated, temperature remaining relatively high 

 for some time after the gale was over. 



The rise of temperature associated with strong winds and gales from a polar quarter, at Victoria Land, 

 has been freely commented on, and has, by some, been attributed to the Fohn effect, to the warming, 

 dynamically, of the air in its descent after passing over the mountain ranges. There is considerable 

 evidence, however, to show that these strong winds from southward had their origin in, and owed much of 

 their relative warmth and their moisture to, lower and warmer latitudes over the ocean. 



It seems probable that areas of low pressure, on their passage eastward north of Victoria Land, after 

 passing the meridian of Cape Adare, not infrequently take a more southerly path, striking south-eastward 

 and penetrating into, or skirting, the Ross Sea. 



Circulating about an area of low pressure, situated over the Ross Sea, the winds would be northerly to 

 north-easterly in the eastern segment of the system, to seaward; easterly to south-easterly in the southern 

 segment, along and over the ice barrier; and southerly to south-westerly in the western segment imme- 

 diately to the eastward of the mountain ranges. 



Thus the southerly wind should be a relatively warm sea wind, coming from lower latitudes, circulating 

 in the western segment of the ocean wind system. 



McMurdo Sound, it is contended, is situated too far south of Cape North and Cape Adare to experience 

 as strong winds the northerly and north-easterly winds blowing in front, i.e., in the eastern segment of a 

 low-pressure system travelling eastward to the north of these capes ; and the locality, moreover, is 

 protected somewhat from northerly winds by the high land to the northward. 



At Snow Hill, the Winter Quarters of the Swedish Antarctic Expedition, conditions were somewhat 

 similar. 



Cyclonic wind systems, travelling eastward, after passing south of Cape Horn, apparently did not, as a 

 rule, during Ur. NOKDKNSKIOLD'S stay on the island, cause an increase of wind there until the system had 

 passed the 56th meridian of west longitude and to the eastward of Joinville Island. Then the wind 

 increased from southward, usually from south-south-west, taking the direction, roughly speaking, of 

 Graham Land and Danco Land and blowing toward the low pressure, still retaining its southerly direction 

 even when the central " low " of the system had passed sooth-eastward into the Weddell Sea. 



To revert to Victoria Laud ; with the arrival of a depression over the Ross Sea the pressure gradients 

 would become steeper, but a marked diminution of pressure over the land to the westward would not 

 necessarily result, and, as observations show, rarely did result. 



At the Winter Quarters of the German Expedition in the Antarctic, during the winter months of May " Gauss'," May to 

 to August, 1902, inclusive, observations for pressure showed a mean of 29 '101 inches, which is 0-071 inch 

 lower than the mean pressure during the same period which obtained at McMurdo Sound. 



The highest pressure for the period at the " Gauss " station, which was recorded on the 16th June, is 

 given as 29-922 inches, and is 0-259 inch lower than the highest pressure recorded on board the 

 " Discovery " for the same period. 



The lowest pressure at the " Gauss " station during the four months referred to, which is as low as 

 27 '808 inches, was recorded on the 1st August, and is 0-332 inch lower than the lowest pressure recorded 

 on board the " Discovery " in those months. 



The range of pressure therefore is found to have been 2-114 inches at the more northern station during 

 the period as against 2-041 inches at McMurdo Sound. 



The mean temperature at the " Gauss " station, from May to August, inclusive, was - 0" -2 F. ; the 

 maximum temperature was 23' "9 F. and was registered on the 7th May; the minimum temperature 

 -41-4 F. and was registered on the 14th August. These extremes give a range of 65 -3 as against a 

 range of 69 5 at the British station during the same period ; the mean temperature at the British station 

 was, however, 13 -1 lower than the mean temperature at the German station. 



