47 



above 14 deg.; this 

 also when compared 



©logical conditions are, with, our present knowledge, quite 

 unaccountable. For instance, why should the barometric 

 pressure be so much less in the south than in the north ? 

 There is probably half an inch of mercury of difference. The 

 effects of this are very evident in the southern zone of south- 

 westerly winds with rain and snow all round the globe, but 

 what is the cause ? Again, we have all read of the short 

 but for the time genial summer of the Arctic regions — why 

 is there none in the Antarctic ? Eoss, when close to the 

 great Victoria land ice barrier writes : — " Gigantic icicles 

 depended from every projecting point of its perpendicular 

 cliffs, proving that it sometimes thaws, which otherwise we 

 could not have believed ; for at a season of the year, 

 eqvivalent to August in England, we had the thermometer 

 at 12 deg., and at noon not rising 

 severity of temperature is remarkable 



with our former experience in the northern seas, where from 

 every iceberg you meet with streams of water are constantly 

 pouring off during summer. 



Another remarkable phenomenon connected with what 

 should be the Antarctic summer is the very small range of 

 the temperature both diurnal and seasonal. In Boss's book 

 the abstract meteorological journals given show for January, 

 1841, a maximum daily range of 12 deg. Pah. and a minimum 

 one of 1 deg.; and for February, 1841, a maximum daily 

 range of 10'5 deg. and a minimum of 15 deg. And last 

 year Mr. Bruce had similar experience in the Balaena. He 

 says in the paper from which I have already quoted : — " The 

 records of air temperature are very remarkable ; our lowest 

 temperature was 20'8 deg. Fab., our highest 37'6 deg. — only 

 a difference of 168 deg. in the total rauge for a period 

 extending slightly over two months. Compare this with our 

 climate, wherein a single day and night you may get a 

 variation of more than ttvice that amount. . . . The 

 average temperatures show a still more remarkable uniformity. 

 December averaged 31T4 deg. for 115 readings; January, 

 3 T 10 deg. for 198 readings; February, 2965 deg. for 116 

 readings — a range of less than 1-J- deg. Fah, From these 

 records of temperature Mr. Bruce and Dr. Murray and other 

 authorities think it very probable that there is a comparatively 

 small range of temperature all the year round in Antarctic 

 regions, and that the cold of winter would not be so terrible 

 as is imagined by some. 



The result of the great amount of precipitation taking 

 place in the zone of low pressure and in a summerless climate, 

 is that the whole coastline of land within the Antarctic 

 Circle is covered with an icecap of enormous thickness. But 

 from observations of the prevailing winds in the south polar 

 regions, it is almost certain that the zone of low barometric 



