THE RENEWAL OF ANTARCTIC EXPLORATION. 365 



Arctic Ocean; in the Southern Hemisphere the open ocean completely 

 surrounds the Antarctic continent, and this open ocean carries with it 

 the low barometric pressure all r<mnd. ^ow, if the low pressure still 

 inrther deepened with increase of latitude towards the South Pole, it is 

 certain that the iirevailing winds over all these high latitudes would be 

 northwesterly and northerly. Jkit the observations made by Eoss, the 

 Challenger, and more recently, in latitudes higher than GO'^ south, by the 

 Dundee whalers and others, (juite unanimously tell us that in these 

 liigh southern latitudes the i)redominating winds are southerly and 

 sDutheasterly. Thus, during the winter of 189L'-'i).3, in latitudes higher 

 tlian (iO"^ south,half of the wliole winds recorded by the D'mna were south, 

 southeast, and east, being directions opposite to tlu' winds which would 

 certainly prevail if pressure diminisluHl steadily to tlie South Pole. 

 Sucli surface currents as have been observed in the Antarctic Ocean 

 come also from south aud southeast. 



All the teaching of meteorology therefore indicates that a large 

 anticyclone with a higher pressure than prevails over the open ocean to 

 northwards overspreads the Antarctic continent. While this anti-cy- 

 clonic region may not bo characterized by an absolutely high pressure 

 at all sea.sons, it must be high relatively to the very low pressure which 

 ])revails to the northward. The southerly outtiowing winds which 

 accompany this anti-cyclone will be dry winds and attended by a small 

 precipitation, it is probable that about 74° south the belt of excessive 

 preci]»itati()n has been passed, and it is eveu conceivable that at the 

 pole precipitation might be very little in excess of, or indeed not more 

 tliau equal to, the evaporation. Even one year's observations at two 

 points on the xVutarctic continent might settle this point, and enal)le us 

 to form a tolerably comi)lete idea of the annual snow-fall and evapora- 

 tion over the whole continent. An approximate estimate might then 

 be given of the a.iuual discharge from the solid glacier rivers into the 

 surrounding ocean. Indeed it is impossible to overestimate the value 

 of Antarctic observations for the right understanding of the general 

 meteorology of the globe. 



Not less interesting than the meteorology of the land area is that of 

 the ocean in southern latitudes. In the neighborhood of the Antarctic 

 Circle the temperature of the air and sea surface is, even in summer, at 

 or below the freezing iioiut of fresh water. A sensible rise takes place 

 ab!)ut the sixtieth parallel, and a temperature of 38"^ F. has been recorded 

 in that latitude in March for both the air and sea surface. The general 

 result of all the sea temperatures observed by Cook, Wilkes, Eoss, aud 

 tiie ChaUenger in the Antarctic Ocean shows that a layer of cold water 

 underlies in summer a thin warm surface stratum aud overlies another 

 warm but deeper stratum towards the bottom. The cold stratum extends 

 like a wedge northwards for about 12°. At depths between 50 and 300 

 fathoms at the southern thick end of the wedge the temperature is 28^ 

 F.I and at the northern thin end of the wedge it inci eases to about 32'0'5 



