THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 305 



continent, and that the Antarctic anti-cyclone is not far distant. The temperature 

 observations show that a cold area lies off the east side of Graham's Land, for at Snow 

 Hill, latitude 64° 22' S. longitude 57° 00' W., the mean annual temperature from two 

 years' observations is only 10°-7 ; while at Port Charcot, latitude 65° S. longitude 64° W., 

 it is 14°-5 ; while over the region traversed by the " Belgica" approximately in latitude 

 70° 30' S. longitude 90° W., the mean was even higher, being 14°-7. At the South 

 Oricneys in 61° S. and 44° W., the mean is about 22°, while at South Georgia, in 

 latitude 54° 31' S. longitude 36° 05' W., it is 35°, so that the isotherms must be very 

 crowded in this region. Indeed, this applies to the whole area lying between latitudes 

 55° to 65° S., and longitude 90° and 20° W. The isotherms over this area may be 

 said to lie in an approximate E.S.E. and W.N.W. direction, bending considerably to 

 the south between the latitudes of 54° and 58° S., and the meridians of 45° and 60° W., 

 where the sea temperature falls off at a rapid rate. Indeed, the further east we proceed 

 the further north does the Antarctic current extend, until on the meridian of 10° W. 

 the polar water embraces an area at least as far as 55° S., causing the isotherms to take 

 a more northerly trend. 



In Summer the isotherms open out very much. At this season we have a large 

 area from 70° to 60° S. in the Weddell Sea, in which the mean temperature only ranges 

 from 29° to 82°. In high latitudes the clearer skies and a suu that sets for but a brief 

 period in these three months, result in a temperature similar to what prevails in lower 

 latitudes, where there is more evaporation and where the large amounts of cloud 

 and fog and drifting ice maintain a temperature almost as low as that prevailing 

 in clearer res;ions 10° to the south. The regional distribution in the amount of cloud 

 depends very much on the presence of the sea, for a cloudy zone does extend to a 

 high latitude where there is ocean, whereas a relatively small amount of cloud may 

 prevail in much lower latitudes over a land surface. The annual mean amount of 

 doud from latitudes 55° to 65° is about 7-5, rising to over S'O at the South Orkneys 

 and over that portion of the region where sea and ice meet. The winters there are 

 much clearer than the summers owing to the continental conditions due to the freezing 

 up of the sea to the south. 



I have in the preceding reports made some reference to atmospheric circulation in 

 the Weddell Sea area, pointing out that as suggested by Neumayer as far back as 1872 

 " the brave west" or rather north-west winds prevailed to at least 62° S. ; while the east 

 wind system is met with in higher latitudes after a zone of varialjles is passed, whose 

 position is determined by the proximity of the Antarctic continent. Thus, at the winter 

 station of the "Gauss," in latitude 66° 02' S. longitude 89° 38' E., 73 per cent, of all 

 the winds were from the east, while on the summer voyage of the " Valdivia" the west 

 wind system was left behind in as low a latitude as 56° S. in 20° li, and east winds 

 prevailed to 65° S. over that portion of the voyage from 20° to 60° E. On the return 

 voyage the west winds were again met with in latitude 55° S. During the summer 

 •cruises of the " Scotia " east winds blew with increased frequency and force to the south 



