842 



DR J. H. HARVEY PIRIE ON 



there was a layer 10 inches thick of granular neve (probably accumulated during March 

 and April), with solid glacier ice below. On 27th May the depth had increased io 18 

 inches. The highest point reached on the stick probably did not much exceed, if at 

 all, 30 inches ; the highest actually noted was 29 inches on 27th November. From this 

 date onwards it gradually fell to 24 inches on 18th December, to 15 inches on 1st 

 January 1904, to 6 inches on 12th January, and to zero on 10th February. These data 

 are shown graphically in the accompanying figure. This means that by 10th February 



Inches 



30- 



25 



ao 



15 



lO ■ 



30 



25 



■dO 



•15 



IO 



May tJuue July ^^q. Sept Ocf: Nov. Dec. Jan Feb. 



Text-fig. 5. — Accumulation and ablation of snow on glacier at Scotia Bay 1903. 



the whole season's accumulation had melted ; but in that respect it does not give a fair 

 representation of the general state of matters, for over the greater part of the ice- 

 sheets the year's precipitation forms a new stratum of neve-ice. It may be mentioned 

 for comparison that the depth of accumulation about the centre of The Beach, probably 

 about as fair an average as could be found, rose to 36 inches. The 30-inch accumula- 

 tion on the glacier represents a considerable precipitation, as it consisted not merely of 

 packed snow but of a mixture of dense granular neve and neve-ice. 



Tkansformation of Snow into N:eve and Ice. 



This state of affairs is brought about by the comparative frequency with which the 

 air temperature rises to 32° F. or over. The table on p. 834 gives the number of days 

 in each month on which the mean temperature of the day was 32° F. or over. In 

 addition to these, there were many days on which the temperature rose to 32° F. or 

 over for a part of the day. Slight falls of rain were also not infrequent at the South 

 Orkneys (see p. 836). During such warm periods a certain amount of the surface 

 snow is melted, and by subsequent freezing into ice becomes, as it were, fixed, and is 

 thus prevented from being swept off by the wind on to the sea ice. 



