834 DK J. H. HARVEY PIRIE ON 



the level of perpetual snow extends down to sea-level, and the summer temperatures 

 even are so low that they are but rarely above freezing-point. It follows that there 

 is no division of the glaciers into a zone of accumulation or formation and one of 

 ablation or melting, their whole extent falling within the accumulation area. The 

 two factors mentioned are those mainly responsible for the characters of the glaciers 

 of this region, characters which are peculiar to the Antarctic. 



Climate. 



The South Orkneys are a little different from other parts of the Antarctic of which 

 we have particular knowledge in their more oceanic position and comparatively 

 low latitude (61°), although much lower latitudes (54°) are not incompatible with a 

 condition of complete glaciation, as witness the case of Bouvet Island (11). 



The following is a brief summary of the leading meteorological factors with a 

 bearing on ice formation — from Mobsman (12). 



Temperatures. 



Mean annual temperature, 22° '7 F. 



Mean temperature of February (the warmest month), 31°'5 F. 



Mean temperature of July (the coldest month), 12°*0 F. 



Seasonal means: — Spring, 23°"3 F. ; summer, 31°*0 F. ; autumn, 22°'6 F. ; winter, 

 13°-7 F. 



Summer mean daily range, 1°"3 F., indicating an oceanic character of climate, the 

 islands being surrounded by more or less open sea. 



Winter mean daily range, 9°"1 F., indicating a continental character of climate, 

 the surroundings seas being more or less completely frozen over. 



Number of days in each month during our stay at the South Orkneys in which 

 the mean temperature of the day was 32° F. or over : — 



April 3 August 1 January 15 



May 3 September February 18 (out of 21) 



June 2 October 5 



July 1 November 5 



Winds. 



Annual percentage frequency :—N. 10-9, N.W. 36-1, W. ITl, S.W. 12-5, S. Q'l, 

 S.E. 9-5, E. 2-1, N.E. 27, calm 5-3, var. 07. 



Mean temperatures of the different winds (April to October 1903): — N. 24°"8, 

 N.W. 26°-9, W. 23°-9, S.W. 7°-4, S. 5°-2, S.E. 5°-6, E. 8°-l, N.E. 22°-4, calm 11°'0. 



Fohn winds occur at Laurie Island with winds from W.N.W., in which direction 

 there is a considerable area of high land over which the wind has to pass before 



