similar to that shown in Table 5 for the observations in the darkest portion of the 

 year. The figures expressing this frequency are given in Table G. 



TABLE 6. Diurnal Frequency of Aurora (70 altitude and over), Cape Evans, 1911. 



The maximum between the hours of 4 and 5 is even more clearly marked than in 

 Table 5, while the complete absence of aurora at this altitude between 19 and 22 hours 

 is clear indication of a minimum about this time. This confirms our previous statement 

 that the tendency of the aurora is to spread to the Cape Evans neighbourhood only at 

 hours of maximum frequency, i.e. in the early morning. 



Aurora in N.W. to W. and W. to 8.W. Sectors. 



The same statement is true for aurorse seen between N.W. and S.W., these sectors 

 being those in which aurora is most seldom observed. On the view that the aurora 

 spreads from the E.N.E. and only passes over the station at Cape Evans into the 

 above two sectors at times of maximum frequency, it is to be expected that the diurnal 

 frequency for aurorse in these sectors would be very similar to that for aurorse seen 

 close to the zenith. Table 7, giving an analysis of the 85 occasions observed in 1911, 



TABLE 7. Diurnal Frequency of Aurora seen between NAY. and S.W., Cape Evans, 



1911. 



shows that the two cases are closely parallel, the maximum, however, occurring earlier 

 in the morning for aurorse near the zenith. 



Aurorce showing Colour and Movement. 



An attempt was also made to analyse the frequency of those cases of aurora in 

 which special mention was made of colour or movement. The number of such cases 

 was very small, but the result which disclosed itself was, that for 17 observations in 

 the forenoon there were 19 observations in the afternoon, a result in direct opposition 



15 



