14 



The prevailing winds at Laurie Island, South Orkneys, the station of the Scottish Antarctic Expedition, 

 during the year 1903 were North-westerly, but Northerly and Westerly winds were rather frequent. At 

 Snow Hill, the Swedish station, the average direction of the wind, from March, 1902, to October, 1903, 

 inclusive, was about South-south-west, the prevailing winds being from South or South-west. When 

 gales occurred they blew almost exclusively from Southward and South-westward. On board the " Scotia," 

 near the ice barrier bordering the land discovered by the Scottish Expedition in latitude 74 1' S., longitude 

 22 W., and named by the leader, Mr. BRUCE, " Coats Land," the prevailing direction of the wind from 

 the 7th to the 12th of March, 1904, the period of the " Scotia's" stay there, was Easterly; and from the 

 7th to the 10th the wind blew with gale force. 



It seems probable that between sea and ice barrier in the southern extremity of the Weddell Sea, under 

 normal conditions, there exists a slight pressure gradient for Easterly winds, and that the gales from 

 Eastward which occur there are the result of a steepening of this gradient associated with depressions 

 centred to the north of the barrier, and moving eastward or south-eastward. 



The Region of Kaiser Wilhelm II. Land. 



At the Winter Quarters of the German Expedition, in latitude 66 2' S., longitude 89 48' W., where 

 the "Gauss" lay frozen in during the period March, 1902, to February, 1903, nearly 53 per cent, of all 

 wind observations were of winds from East-by-north, East, and East-by-south ; 73 per cent, being from 

 directions in the eastern half of the horizon; 16 per cent, from directions in the western half; and 11 per 

 cent, being noted as calms.* The Easterly winds were stronger than those from any other direction ; out 

 of 793 hours of strong winds, recorded in the course of twelve months, no less than 90 per cent, were 

 from East-by-north, East, or East-by-south. 



From the 28th April to the 10th May, and again from the 28th September to the 9th October, periods 

 of 13 and 15 days respectively, meteorological observations were obtained at the foot of the Gaussberg, a 

 mountain situated in latitude 66 48' S., longitude 89 30' E., on the verge of the inland ice barrier, 

 53 miles south from the " Gauss." By comparing the observations of barometric pressure taken at this 

 station with those obtained on board the " Gauss," it was found that pressure was slightly higher at the 

 foot of the mountain than it was on board the ship. During the earlier period the difference amounted to 

 1-7 mm. (0-067 inch), and during the latter to 0'8 mm. (O'OSl inch). 



This slight increase of pressure landward was thought to be confirmatory of an inference that had been 

 drawn from the direction of the prevailing wind that pressure increased with latitude southward. 



Whether this be the case or not, the frequency of winds from Eastward is doubtless due to the existence 

 of a pressure gradient between land and sea, and to the general east and west trend of the coast line. 



The steepness of this pressure gradient is increased, and Easterly gales occasioned, by the incursion of 

 eastward moving low-pressure wind systems. The Easterly gales experienced by the German Expedition 

 at the " Gauss " station were always attended with a steady rise of air temperature, the thermometer 

 continuing to rise until the wind had attained its maximum force. This increase of temperature associated 

 with gales from Eastward may be regarded as a proof that the winds have their origin in lower, warmer, 

 and possibly in tropical latitudes over the ocean, and that they form part of the circulation of eastward 

 moving cyclonic systems, flowing in front of their centres ; for during gales from Westward at this station 

 there was always a fall of temperature. The remaining part of the air from the Northward, which, by 

 circulating in rear of these central " lows," had parted with its heat during its passage over the Antarctic, 

 is reinforced by air from polar regions, and occasions a fall of temperature. 



The Westerly winds that are shown by the charts to occur occasionally at Kaiser Wilhelm II. Land 

 immediately after a cyclonic depression has passed eastward to the north of the " Gauss " station, may 

 belong to the wind system of a secondary depression, and the fall of temperature with which it is attended 

 may be due to the introduction of air of polar origin into the circulation of this secondary. 



It will be seen from the foregoing that, as a result of the wind circulation set up during the passage 



"Wind Conditions at the 'Oauss' Winter Quarters," by Dr. WILH. MKINABDUS, Berlin, ' The Proceedings of the 

 Fifteenth German Assembly of Geographers at Danzig in 1905.' 



